Royalty certificate requirement under section 80QQB requires publisher verification of payments and agreement details to authors. Form No.10CCD under section 80QQB requires publishers to certify payments to authors, providing book identification, author details, sales in India and abroad, the nature of the payment arrangement (lump-sum, assignment, or royalty), and amounts received in Indian rupees and foreign currency. The certificate must include a proforma for foreign currency payments and a signed verification by the publisher identifying the payer by Permanent Account Number or Aadhaar and confirming payment to the author.